Telephone-transmitter



(No Model.)

WpO. LOGKWOOD.

TELEPHONE TRANSMITTER.

Patentd Aug. '14, 1883.;

.I .U lfi lw Nv PETER wise.

WILLIAM G. LOOKWOOD, or 'BRooKLYmn. Y., ssrcnon TO DORRANOE, F NEW YORK.

. PATENT OFFI E.

CHARLES J.

TELEPHONE-TRANSMITTER.

SPECIFICATION forming part of Letters'latent No. 283,123, dated August 14, 1883.

' Application fiiean rnaz, 1882. (No model.)

To all whom it may concern:

Be it known that I, WILLIAM G. LooKwooD, of Brooklyn, Kings county, in the State of New York, havejinvented certain new and useful Improvements Relating toTelephonerTransmitters, of which 'the following is a full and exact description, reference being had to the accompanying drawings, forming part of the same, in whicht .Figure 1 is a central longitudinal section through the electrodes and the immediately adjacent parts, as also through the parts which sustain the electrode and constitute the principal parts of the transmitting-instrument. Fig.

2 is a corresponding section through a modification of the central parts, which involve the novelty. i

Similar letters of reference indicate corresponding parts in both-the figures.

The invention lies in the mode of mounting and connecting the gas-carbons or other pieces of material constituting ,the electrodes. 1 attain unusual security with the requisite mobility.

Referring to Fig. 1, G is the upper electrode,

and G the lower electrode, connected to the respective wires, as usual, and fixed one to a diaphragm agitated by the wire and the other to suitable supporting means adjustable by the turning of the screw H, as will be understood.-

a The ends of the electrodes 0 and Gare plane,

and finished. smoothly by grinding or other- The sides or cylindrical surfaces of each are coated with rubber cement w. Upon each is then slipped a ring W, of vulcanized rubber of the ordinary grade, known as soft,

care being taken to slip each on from what is to form the inner end or the a contact end of the electrode. This wipes or carries the cement away from the contact point or line, or rather plane, leaving the soft rubber cemented to the electrode strongly atthe outer endand less and less strongly toward the contact end. When the cement has perfectly hardened, so as to not allow the displacement of the rings upon the electrodes, the exteriors of the rings are covered withathin coat of cement, and each elecdense casing-until the plane faces of the electrodes are in firm contact each with the other, and the cement is all owed to set with the parts tion is now ready to be screwed, cemented, or

otherwise joined to a diaphragm, B, in'closed in a stout cup, A, of well-dried wood or other non-conducting material, joined by the wires D andE tot-he proper connections for operating, and when the electrodes are properly forced together by the adjusting-screw H, to securethe proper contact of the surfaces of the electrodes, the device will serve in the usual.

manner, the rigid tube or ring Z givingavery strong support, and the rubber rings W Wallowing the endwise motion of one electrode relatively to the other, required for the proper varying of the force of contact.

As the partial or complete making and breaking of contact induces heat and oxidation of some particles of the electrodes, the oxygen in the air inclosed becomes combined, and the oxidation of the electrodes ceases because of the com- The tight plete exclusion of further oxygen. contact of the elastic rings W W with their respective electrodes 0 andG on their inner ment applied on bothsurfaces, makes the joint perfectly airtight. I attach much importance to the cement as a means of insuring not only great firmness of place of the several parts, ex-

cept as the soft rubber WV W shall yield to allow the very slight motions required, but also The i of insuring absolutely air-tight joints. shoulders formed by the reduction of the diam eter of each electrode at the end farthest from contact allow considerable thickness of rubber W, while the airspace inclosed is still very slight. I do not esteem these shoulders absolutely indispensable. Fig. 2 shows a formin which thinner rings W are employed, and the'bearingsthereof upon the respective electrodes are made longer, and no shoulders or contractions are made in the electrodes. It is still more important with; this form to apply 80 faces,.andwith the rigid ring or tubeZ on their r outer faces, aided by the coating of rubber cethe soft-rubber rings W by slipping them on from the contact ends of their respective electrodes.

Further modifications may be made in the -forms and proportions and in the materials employed without departing from the principle or sacrificing the advantages of the inven tion. I can have two or more planes of contact by employing one or more pieces of gascarbon or other suitable material between the electrodes 0 and G, the latter being mounted sufficiently far-apart. In such case each such intermediate piece should be enveloped in soft rubber, taking care to leave the portions at and near the contact-planes free from cement, and'the exterior of the soft rubber should be cemented to the interior of the rigid tube. I prefer to use but two electrodes, as shown. I can, if desired, shellac-varnishthe non-contact surfaces of the electrodes before they are put in position, and again varnish over the ends I claim as my invention- 1. The electrodes 0 and G, soft rings WV, cement w, and rigid ring Z, combined and arranged as and so as to serve as herein specified.

2. The rigid cup A, diaphragm B, and adjusting-screw H, in combination with each other and with the electrodes 0 and G, and with the rigid ring or tube Z, elastic rings W, and cement w, arranged as herein shown and described. t g

3. In atelephone-transmitter, a non conducting tubular covering inclos'ing both electrodes and making an air-tight case therefor by the aid of cement w, which forms-a tight seal at both ends, substantially as herein specified.

4. The combination, with the two electrodes in contact with one another, of a rigid ring or tube, Z, with which said electrodes are con WM. 0. LocKwooD.

Witnesses:

THOMAS D. STETSON, R. D. 0. SMITH. 

